Economic Policy of Horizontal Competition Restraint

本文的主要研究内容有：(1)附加费对卡特尔威慑作用的研究，以及适宜的附加费制度的研究。(2)市场全球化对主要行业的全球市场集中度；(3)不同企业战略对市场集中度和经济福利的影响。我们的结论是，基于损害的附加费制度在提高卡特尔产量的意义上是首选的。至于(2)，我们发现，尽管自20世纪90年代末以来出现了多次并购，但最近主要行业的集中度并没有那么快地上升。然而，我们发现，并购和多种类型的联盟提高了企业集团计算的集中度。至于(3)，我们从竞争政策的角度考虑了日本航空和日本航空系统的整合问题。我们指出，应该收回更多的起降时段，以鼓励新的进入；合并后由同等竞争的航空公司组成的双寡头垄断可能比由一家主导公司和两个边缘组成的寡头垄断更容易串通；以及在超级特快列车不能很好地替代乘客的路线上，竞争可能受到限制。此外，我们还考虑在解除管制后，日本公平贸易委员会对机票进行干预。我们的结论是，干预机票价格对于阻止掠夺和保持市场的长期竞争是必要的，但应该分析价格-成本关系，并明确降价的长度和顺序。

Our major research topics are : (1) the effect of surcharge on the cartel deterrence, and study of the desirable surcharge system. (2) worldwide market concentration of major industries due to the market globalization, and (3) the effect of the various corporate strategies on the market concentration and economic welfare.As for (1), we analyzed theoretically the effect of various surcharge bases and surcharge rates on the cartel deterrence and economic welfare. We conclude that the surcharge system based on damages is preferred in the sense that it can increase output of a cartel.As for (2), we find that the concentration ratios of major industries are not increasing so rapidly recently when we see the concentration trends after 1980s, even though we have seen many mergers and acquisitions since the late 1990s. However, we find that the mergers and acquisitions, and many types of coalitions raise the concentration ratios calculated by groups of firms.As for (3), we consider the problems of consolidation of Japan Airlines and Japan Air System from the viewpoint of competition policy. We point out that the more slots for departing and landing should have been returned for encouraging new entry, that a duopoly of equally competitive airlines after merger may be easier to collude than oligopoly which consists of one dominant firm and two fringes, and that competition might be restricted on the routes where the super express trains are not good substitutes for passengers. Also we consider intervention in airfares of Japan Fair Trade Commission after the de-regulation. We conclude that intervening in airfares was necessary to stop predation and keep long-run competition in the market, but price-cost relationship should have been analyzed, and length and the order of price-cut should have been specified.